code: def test_vert_flip_buffer(self):
      noop = np.array([0, 0, 0, 0, 0, 0, 0], dtype=np.intc)
  
      env0 = deepmind_lab.Lab(
          "tests/render_test",
          ["RGB", "RGB_INTERLEAVED"],
          config={
              "fps": "60",
              "width": "512",
              "height": "512",
              "randomSeed": "1",
              "vertFlipBuffer": "0",
          },
      )
      env0.reset()
      self.assertEqual(env0.step(noop, 1), 0)
      image0 = np.transpose(env0.observations()["RGB"], (1, 2, 0))
  
      env1 = deepmind_lab.Lab(
          "tests/render_test",
          ["RGB", "RGB_INTERLEAVED"],
          config={
              "fps": "60",
              "width": "512",
              "height": "512",
              "randomSeed": "1",
              "vertFlipBuffer": "1",
          },
      )
      env1.reset()
      self.assertEqual(env1.step(noop, 1), 0)
      image1 = np.transpose(env1.observations()["RGB"], (1, 2, 0))
  
      # Test skydome pixels.
      np.testing.assert_array_equal(image1[0, 0], [150, 224, 255])
      np.testing.assert_array_equal(image1[0, 511], [150, 224, 255])
  
      np.testing.assert_array_equal(
          image0, env0.observations()["RGB_INTERLEAVED"]
      )
      np.testing.assert_array_equal(
          image1, env1.observations()["RGB_INTERLEAVED"]
      )
  
      # Delta between original and reversed flipped observations.
      # Images won't be identical due to texture sampling and aliasing biases
      # depending on the direction of rasterisation.
      np.testing.assert_almost_equal(
          np.average(abs(image0 - np.flipud(image1))) / 255,
          0,
          decimal=2,
      )
  
file_path: lab/python/tests/render_test.py
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import os
  from absl.testing import absltest
  import numpy
  import deepmind_lab
label_desc: Use image node_id 1 for calling the RenderTest obj's underlying member method code with example usage: obj.test_vert_flip_buffer() without return types